Hi,
I had the same kind of question. Do you know what this programing language is called please ?
Anyway, what does @{ } do ?
If you want to use the value stored in your variable, you have to use it with {{ }} like :
{{call_req_id.z_ebene_sap}}
and actually you also have to replace the . by _
For instance if you want foo.bar value (attribute bar of object foo) you put it like that : {{=foo_bar}}
Same goes for the request parameters : {{=request_URLPARAMETER0}}
Lambert Rosique.